She is hardly alone. There are raised hands and stifled laughter all around her. “This is shameful,’’ one student says. “This is why we need to go camping,’’ says another.

This is Yerba Buena High School in San Jose, but it could be anywhere that combines teenagers and a decent Wi-Fi connection. It is here, in classrooms just like this one, where we’re repeatedly discovering the often-unexpected ramifications of how technology is redefining our lives.

Along with you, this newspaper has spent weeks now taking a look at the rapid recasting of our existences into a frenetic, hyper-connected, ultra-stimulated, all-knowing experience of overlapping tasks and interactions.

Now, for the final installment of our eight-part series, we focus on the consequences of this digital frontier: from the way technology is rewiring our brains to the way social media are rewriting how we talk to our friends, torment our enemies, tout our triumphs – and embarrass ourselves in public.

We’ve reached out to brain experts, elementary school teachers, college professors, school administrators, tech innovators — and the kids at Yerba Buena High — to ask a pressing question of our age: What hath our gadgets wrought?

And when they’re awake? Forget it. Teenagers have been found to cram 11 hours of media content into just 7½ hours because they are using multiple screens at once.

Chuck Byers, an adjunct professor at Santa Clara University, sees evidence in his classroom every day. “We were always worried about Big Brother sucking the intelligence out of our minds? Well, the Internet has done that. Our attention span is two paragraphs,’’ he cracked.

But rather than lamenting the evolution, Byers embraces it. In his communications class, he advises his students to keep their messages clever and punchy — to speak in the language of the times. The days of the 20-page dissertation are dead, Byers said, and he has an assignment he calls a “Tweet-tation” that does a better job of preparing students for the modern workplace.

“I want people to be able to tell me the history of the world in 100 words or less,’’ he said. “That’s sort of the number of words that appear on a computer screen at any given time.”

Big moments in CONSEQUENCES Some milestones of consequences

Rants about the boss are as old as time, but tweets about the boss are a recipe for unemployment. Disgruntled 49ers running back Brandon Jacobs was one of many to discover that when he was suspended and then cut from the team after taking to social media last year to whine about his lack of playing time and boss Jim Harbaugh.

An unexpected firestorm followed a female tech developer’s outing of two engineers on Twitter for making what she described as sexual jokes during a Santa Clara tech conference last summer. “Not cool,” she wrote. One of the engineers lost his job, and so did the tweeter, Adria Richards, who endured a vicious backlash for going so public with her complaint. Her company SendGrid, which became the target of a cyber attack, explained in a statement why it was terminating her: “In the end, the consequences that resulted from how she reported the conduct put our business in danger.”

New York congressman Anthony Weiner became one of the first great casualties of the unmistakable consequences of a self-inflicted tweet when he infamously sent a follower a link to a closeup of his boxer-clad privates that was anything but private.

Crime fighters are looking to social media to help make the case against suspects with a penchant for bragging about their exploits — like an East Bay teen who allegedly killed a cyclist while topping 80 mph. When prosecutors found a history of tweets, one boasting of driving 140 on the freeway, another “drive fast live young” — they upped the charge to murder.

In the latest example of career-suicide-by-tweet, a South African-born public relations executive for the Barry Diller-run Internet company IAC inexplicably unleashed this mind-boggling tweet. By the time she touched down in South Africa, her tweet had circled the globe, and her job was toast.

Multi-tasking is so distracting

But this click-and-run mindset might move too fast at times, at least as far as the human brain is concerned. The truth is, most people are lousy at multi-tasking (witness the 1.3 million car crashes in 2011 that involved cellphones).

Then why do we do it? Researchers at Ohio State University concluded that multi-tasking gives students an emotional boost, even when it hurts their cognitive functions, such as studying.

“There’s this myth among some people that multi-tasking makes them more productive,” said Zheng Wang, lead author of the 2012 study, on the school’s website. “But they seem to be misperceiving the positive feelings they get from multi-tasking. They are not being more productive — they just feel more emotionally satisfied from their work.”

At worst, we are a nation with our heads down. On a San Francisco Municipal Railway car on Sept. 23, commuters were startled by the sound of the gunshot that killed Justin Valdez as he was exiting the train. Apparently, investigators say, fellow passengers were so distracted by their smartphones that they failed to notice the suspect had earlier pulled out his gun three or four times on the train.

Empathy, that connection that makes it more likely to help people in need, is on the wane in the digital age. Researchers at the University of Michigan found an overall decline in empathy in a study of college students from 1979 to 2009, especially since the year 2000.

“The biggest thing seems to be a loss of empathy, or what we call ‘social prosody’ — the ability to recognize things like sarcasm, humor or even the emotions on a human face,’’ said Dr. Louisa Parks of the Brain Health Center at California Pacific Medical Center in San Francisco.

Parks and Dr. Catherine Madison, in a joint interview at the Brain Health Center, said they sense that people are spending so much time communicating through their devices, instead of face to face, that they sometimes struggle with basic human interaction.

People can interpret emoticons. It’s those real-life frowny faces that give them trouble.

“We’re very worried, and we should be,’’ Madison said.

“I have a knot in my stomach just sitting here,’’ Parks agreed.

LIPO CHING/STAFF

Yerba Buena High School senior Kimberly Nguyen holds up her hand in response to a question about text messaging. Nguyen was one of the few in the class who surpasses 100 texts per day. Also pictured, in front row from center, are sophomores Dorothy Nguyen and Carolyn Nguyen and, in the back row from left, seniors Amanda Ga and Aracely Gomez.

Gut-punches from the dark

At Yerba Buena High, there’s no need for studies. Anyone who has ever clicked on a message board or experimented with social media knows that there are gut-punches that come from the dark.

We asked students via an anonymous survey if they’d ever been the subject of an embarrassing message or rumor circulated among friends. The stories were troubling.

“People called me a whore,’’ one girl wrote. “It’s easier to be mean over the Internet or behind a screen. It’s easier to gang up on people on the Internet, too.”

When the class picked up the discussion, the consensus was clear: “People online get bolder because they are behind the message board,’’ senior John Cash said. “They think, ‘Oh, ha ha ha. I just insulted you. I’m in my home. You can’t reach me.’ … Online you have more power, but it’s not the kind of power that’s good.”

This netherworld exists beyond the full reach of parents, school officials, law enforcement and even the Internet giants. Cyberbullying — a word that entered the Concise Oxford Dictionary in 2011, on the same day as “sexting” and “retweet” — has become a defining issue in adolescence.

Bay Area teens are well aware of the tragedy of Audrie Pott, the Saratoga High student who was bullied, assaulted and humiliated to the point where she took her own life after a digital photo circulated of her passed out at a party with crude messages scrawled on her body.

The notable cases of cyberbullying mount, from Steubenville, Ohio, to West Islip, N.Y., to British Columbia.

“We are faced, in education, with one more layer of keeping kids safe at school,’’ said Kathie Kanavel, Santa Clara Unified School District’s director of Educational Media & Learning Resources. “It adds a huge challenge for both the kids and for the adults. Because everyone knows that technology gives people the ability to be anonymous and to do things that your parents and your teachers aren’t up to speed on.”

Social media are where kids post embarrassing photos and reckless rants and speak in a language that might seem indecipherable to anyone over 30. How can adults have a “fomo” — fear of missing out — if they don’t know what it means?

But the kids are learning that their posts have consequences — and the consequences of yesterday’s slip-of-the-tongue and spur-of-the-moment selfie are perilous. In a telephone questionnaire of 381 college administrators conducted by Kaplan Test Prep, 31 percent said that they had visited an applicant’s Facebook or other personal social media page to learn more about them.

Often, the damage to one’s reputation can be self-inflicted. Embarrassing social media posts that can harm future job prospects and doom college applications are such an epidemic that the California Legislature intervened. In September, Gov. Jerry Brown signed the so-called “online eraser bill” that gives minors in the state the right to remove videos, pictures, recordings, and comments they posted or stored on websites, social media or apps.

At left, Brett Somers tries the Strummify program, which helps beginners learn how to play the guitar, at the 16th annual Learning, Design and Technology Expo at Stanford University.

Maria Molfino, a masters candidate in Stanford's Graduate School of Education, created “Maketea,’’ a mobile app that, in conjunction with a physical tea kit, takes users through a Chinese tea ceremony.

From left, Yerba Buena High School seniors, Xochitl Topete Ventura, Darian "Tyrone" Powell, John Cash and Viviana Zaragoza take a break between classes. “Growing up with technology and advanced media, it’s hard to stay away from your phone, even for a minute,’’ Cash says.

PHOTOS BY LIPO CHING/STAFF

The kids will be all right

But is it really as bad as all that? Or are we overreacting to those changes, the way Socrates did when he fretted that the written word would “create forgetfulness in the learners’ souls because they will not use their memories”?

Across the Bay Area, there are signs the kids will be all right.

While the social media missteps of students are well documented, less breathless are reports about how such searches can work to a student’s advantage. Ambitious, clever teenagers have figured out how social media give them a head start on their dreams.

Tacy Trowbridge, with Adobe Education Programs, recalled going to a national arts awards ceremony for high school students. One of the speakers asked for a show of hands among teens who had digital portfolios for selling and showcasing their work.

“And I was astonished that more than half the students raised their hands,’’ Trowbridge said. “They were conscious about the work that they were creating and the means that were immediately accessible to them to gain an audience.”

And for all the concern over our online meanness, there are just as many random clicks of kindness and compliments.

Yerba Buena senior Darian “Tyrone” Powell discovered just that when his dance crew started sharing its videos online and quickly scored paying gigs.

“We started by posting one video and people are like, ‘Hey, these guys are pretty good,’” Powell said. “We couldn’t have done it without social media like Facebook or YouTube.”

At a Learning, Design and Technology Expo this year, Stanford masters candidates from the university’s Graduate School of Education seemed determined to enhance — not replace — human communication. Maria Molfino, for example, created “Maketea,” a mobile app that, in conjunction with a physical tea kit, takes users through a Chinese tea ceremony, Gongfu Cha.

“The idea is that the couple has been spending a lot of time alone, together,” Molfino said. “So what if we could use technology that would bring us together and facilitate conversation?”

Across the hall at the expo, DesignDuo, a do-it-yourself kit, aimed to get 11-to-13-year-old girls interested in STEM (science, technology, engineering and math). Kirti Patel and Laura Bruursema built the kits figuring that one path to keep girls on a science track was having them design and create things with their dads.

Forging that connection — the human and the digital — is the goal for educators like Deila Caballero, digital media educator at San Jose’s Presentation High School.

“We’re in the center for technology right now,” she said. “And, 10 years from now, I want to see students who appreciate technologies but don’t depend on them. Students who are learning how to think but not what to think.

“We can’t be stagnant. When the new thing comes out, we need to be ready for it.”

Looking back, despite our view from the center of all this innovation, it’s clear we are only beginning to comprehend the consequences of all that’s changed: how dependent we have become on social networks and smartphones to survive; how high-tech pings and dings elbow their way into our most intimate moments yet feed our insatiable need for instant reward; how privacy has become some quaint, old-fashioned pre-iPhone expectation; how simple it is to connect with a stranger across the globe, and lose touch with a loved one across the dinner table.

Ten years ago, no one — not even the digital natives of Yerba Buena High — would have been ready for that.